Fluid actuated mechanism



June18,1946. Z1. M. SHIMER 2,402,300

FLUID ACTUATED MECHANI SM Filed 001. 25, 1941 5 sheets-sheet 1 June 1s, 1946.' J, MQ sHlMER 2,402,300

FLUID AGTUATED MECHANIS'M Filed Oct. 25, 1941 3 Sheets-Sheet 2 dobn M 5/7/'mer' 5 Ng l 49 \k\\ 3mm June 18, 1946.

J. M. sHlMx-:R l

' FLUID ACTUATD MECHANISM Filed oct. 23, 1941 5 sheets-sheet 3 .Patented'tune 18,

srA'rEs PATENT orties FLUID Ac'rUArEn rmcnANrsM l John M. Shimer, Dallas, 'llex. Application October 23, 1941, Serial No. 416,180

vide an improved actuating mechanism for con-` trolling the operation of a piston by alternately supplying a predetermined volume of hydraulic duid to the opposite sides of the piston to reciprocate the same, whereby said piston may be perated from the surface by a fixed, constant quantity of uid without employing the usual sucker or pump rods, and whereby the stroke of thepiston may be lengthened to permit a reduction in the number of strokes per volume of well fluid lifted; the ud applied to one side of said piston being released upon the applicationof .uuid to the other side thereof so as to permit operation of the piston by an actuating fluid of relativelyv low pressure.

Another object of the invention is vto provide an improved actuating mechanism, of the characterk described, wherein the actuating uid is supplied to the piston by surface control means which is snychronized therewith and with the sur'- face pump, whereby the reciprccation of said piston is positively controlled at the surface.

A particular object of the invention is to P IO- vide an improved actuating mechanism for operating a well pump which includes a pump plunger of the displacement type having an actuating member connected thereto for recipro.

eating the same, together with a .rotary control valve at the surface for delivering a predetermined quantity of actuating uid to the member, whereby the reciprocation of the plunger is con trolled directly by the rotation'of the Valve and whereby it is unnecessary to admix the actuatins fluid with the well iluids.

A further object of the invention is to provide 11 Claims. (Cl. 6th-52) the invention is to provide an i till another object of the inventionis to provide 'an improved mechanism, of the character described, wherein the flow of the actuating fluid to the reciprocating piston is through conductors separate from the well iuid column so asl to prevent mixture of said fluids, and wherein the fluid applied toand released from the surfaces of said .piston ows through the surface control valve which is constantly rotating in synchronization with the reciprocation of the vpiston so as to effect a smooth, continuous operation of the plunger without interruption. i

Another object of the invention improved actuating system for a reciprocating mechanism which consists of supplying a predetermined constant quantity of operating fluid for each reciprocation of the mechanism and propor tioning .the quantity of the fluid delivered for each stroke of said mechanism, whereby a uniform continuous operation of the mechanism is had.

A further object' of the invention is to provide an improved system of elevating fluids whichlconsists of supplying a given constant volume of actuating liquid for a single cycle of accumulation and elevation of the well iiuids and proportioning the delivery of the actuating fluid in accordance with the volumes required to accumulate and elevate said Well uids so as to eiect a smooth, confrom a reading of the following specification vand by reierence to the accompanying drawings, as l an example of the invention is shown, and where- Figure 1 is a schematic planview of an actuatingmechanism, constructed in accordance with the inventionand showing the position of the valves during the downstroke of the piston plunger,

Figure 2 isa view, similar to Figure l, showing the positions of the valves duringthe'upstrokev of said piston,

Figure 8 isv an enlarged-longitudinal, sectional is to provide an view of the rotary valve during the downstroke of the piston,

Figure 4 is a cross-sectional view. taken on the line 4 4 of Figure 3,

Figures- 5, 6, 7 and 8 are cross-sectional views taken on the. lines 5, .5 5, 1 1 and 5 5. respectively, of Figure 3, showing the relationship of various portions of the valve element and A housing during the downstroke of said piston,

Figures 9, 10, 11 and 12 are views, similar to 10 Figure 13 is a schematic plan view showing a 15 modified form of actuating mechanism, and

Figures 14, 15, 16 and 1'1 are transverse, vertical, sectional views showing the positions of the valves and cams of the modined form during the downstroke of the piston, the positions during 2u upstroke of said 'piston being shown in dotted lines. -v

In the drawings. the numeral I5 designates the usual well casing which extends substantially throughout the entire length of the well bore and which has its lower end open so that the well fluids may enter the casing and flow upwardly therein. `A well tubing II depends axially within the well casing, being suspended from a well head I2 mounted on the upper end of said casing 30 and being packed-off from the head by suitable packing I2'. The lower end of the tubing ter'- minates at a point above the lower end of the casing and has the conventional perforated pipe I5 secured thereto, For controlling the ilow of 35 the well fluid from the perforated pipe I5 to the tubing, a standing valve I4 is interposed between said pipe and tubing. Immediately above the standing valve. a suitable packer I5 surrounds the tubing and engages the wall of the well casing so as to pack oi! the annular space between said tubing and casing. A displacement chamber I5,

. which has its upper end communicating with the annular space between the casing and tubing by an upwardly-opening check or discharge valve I1 disposed within said space and its lower end in communication with the pipe I5, is provided at the lower end of the tubing.

A cylindrical sleeve I8. of a greater diameter than the tubing, is connected in said tubing and is spaced above the displacement chamber by an inter-connecting section of tubing 24. Disposed within the sleeve I5 is a cylinder Ia which extends axially substantially throughout the length of said sleeve and which is of a'smaller diameter 55 than said sleeve to provide an annular space 25 therebetween. Communication between the lower end of the cylinder I5 and the space 25 is established by a plurality of ports 2i formed in the lower end of said cylinder. A piston 22, hav-- so ing an elongate plunger 25 depending axially therefrom, is mounted to reciprocate within the cylinder I5 and is adapted tobe actuated by hydraulic fluid admitted alternately to the upper and lower ends of said cylinder. The plunger 25. `5

which is of substantially the same'diameter as the internal diameter of the tubing 24 so asto have a snugI sliding lit or engagement therein, is of suillcient length to extend into the chamber I5 when the piston 22 is within the lower portion 70 of the cylinder I5. Since the plunger is solid in cross-section, downward movement of the same through the chamber will force the well fluid admitted thereinto by the standing valve I4 out between the tubing and casing. The diameter of the plunger is substantially equal to the internal diameter of the tubing section 24 which connects the displacement chamber and the sleeve I5 so as to have a sliding flt therein, this sliding ilt' or engagement serving as a seal between said chamber and sleeve to prevent the passage of iluid from one to the other. For admitting a hydraulic :duid to the upper end of the cylinder I5, a maca- 'roni string 25 extends axially through the tubing II and is secured to and packed oi! from the upper extremity thereof by suitable means 25'. Due to the provision of the depending plunger 23, it iS obvious that the lower surface of the piston 22 is of less cross-sectional area than the upper surface thereof, whereby a greater volume of fluid is required to move said piston downwardly -a given distance than to raise the piston the same distance.

For controlling the flow of iluid to the tubing Il andvmacaroni string 25, a rotary control valve 25 is provided at the surface and consists of a cylindrical, horizontally-disposed housing 21 having a tubular valve element 25 rotatably mounted therein, as will be hereinafter more fully described. Communication between the tubing and the valve 26 is established by a suitable conduit 25, while a pipe 50 connects said valve to the macaroni string. One end of the valve element 25 projects beyond the valve housing 21 and has a sprocket 3i mounted thereon. whereby said element may be positively rotated in a clockwise direction (Figures 4 to l2) by the shaft 52 and sprocket 33 of a suitable pump 54, the sprocket 83 being connected to the sprocket 2| by a continuous chain 55. The pump 54. which is preferably of the positive displacement type and which housing 21 and disposed within the same horizontal plane. A pair of similar, horizontallyalin ports 45 -and41 are disposed between the ports 44 and 45 for receiving the lpipe 45 and its branch 45, the plane of the latter ports being diametrically-opposed to the plane of the former ports. The ports 44, 45, 45 and 41 communicate with arcuate or semi-circular recesses 54, 55, and 51, respectively. which are formed inthe bore 45 of the valve housing. The recesses 54 and 55 are of the same circumferential length and are disposed within diametrically-opposed planes. while the circumferential length of the recess 55 is equal to the circumferential length of the recess 51 and said recesses are also disposed within planes diametric to each other.

Each end of the horizontally-disposed valve housing 21 is enlarged to provide an external,

radially-extending flange 55 which is provided with a radial port 5I for receiving the conductor 25 and pipe 55. respectively. As is clearly shown in Figure 4,. each port 5I communicates with an annular groove or channel 52 formed within the bore 45 of the valve housing. The tubular valve element 25 is disposed within the bore 45 of the valve housing and 'has an external diameter subthrough the check valve I1 into the annular space 15 stantially to-the? diameter of said bore,

. whereby the exterior of said valve element snugly engages the wall of said bore. Each end of the element is reduced in diameter and is journaled valve housing and has the sprocket 3| splined upon its outer extremity as 'shown at 55. For packing off around this projecting portion of the valve element, a stufling box 51 is preferably made integral with the forward closure member `54 and includes the usual packing element 58 and gland 59, which is adjusted by bolts as shown.

The valve element 28 is .provided with an axial bore 58 which is closed at each end by suitable end members or plates 5| and which is divided by a transverse partition 52 into two cylindrical,

axially-alined chambers A and B. communica# tion lbetween the chamber A and recess 55 is established by a pair of horizontally-aimed stant communication with said chambers B and A, respectively. y

From the foregoing. it is obvious that the cham-l ber A serves to establish Ycommunication between the ports 45 and 5| by means of the forward groove 52, opening 5 3, oriiices 85 and recess 55,

while the chamber B likewise functions to connect the port 41 to the rear port 5| through the recess 51,' orifices 81, rear opening 53l and rear groove 52 when the valve elementis in the position shown in Figures 1 and 3. In this position of the element 28, the pipe 30 will communicate `with the Y 42 of the conduit 4| and the conductor 28 will be, in effect, connected to the' branch 48 of the return pipe 43 (Figures 4, 6 and 8) whereby the operating uid may iiow from the pump 34 through the valve to the macaroni string 25 into the upper end of the cylinder. i9 so' as to force the piston 22 and its plunger 23 downwardly, and the spent operating fluid within said cylinder below said piston may escape through the ports 2| into the annular flow space 28 so as to displace the iiuid therein upwardly through orifices 85 which extend through the wall of the valve element. A similar pair of orifices 85, which are disposed in the same horizontal plane as the orifices 85, establish communication between the recess 85 and chamber A as shown in Figures 3,

7 and 8. The recesses 54 and 61 communicate with the chamber B through identical orifices 84 and 81, respectively, the orifices being disposed within the same horizontal plane which is diametrically-opposed to the horizontal plane of the orices 85 and 85 (Figures 5 and 6). Although f the orifices 85 and 85 are disposed within the same horizontal plane, the latter orices are out of registration with the recess 55 during the time the -former orifices are in communication with the recess 55. Conversely, the oriiices 85 are in the orifices 85 are out lof registration with their recess 55. This isalso true of the orifices 84 and 81 because their respective recesses are also discommunication with their recess 55 at the time posed within diametric planes. Due to `theirre spective size and relationship, the oriiices 85 communicate with the recess 55 simultaneously with the registration of the orifices 81 with the recess shown in Figures 9 to l2. 'I'he orifices 84, 85, 85v

and 81 are spaced longitudinally of each other so as to prevent fluid from leaking from one pair of orifices to another, the metal-to-metal seal provided by the snug engagement between the housing bore 48 and the valve element assuring non-leakage.

The annular grooves 52 of the valve housing and bore 48 constantly communicate with the chambers A and B by means of openings 53 formed in the valve element 28'and continuously registering with said grooves. Due to the constant registration of each opening 83 with its groove 52, the conductor 28, which is screwfthreaded into the rear port 5|, is in constant communication with the chamber B, and the chamber A communicates at all times with the pipe 30 which is secured within the forward port 5|, whereby the tubing Il and macaroni string 25 are in conthe tubing Il, conductor 29, then through said valve, branch 48 and return pipe 43 into the storage tank 40.

When the valve element rotates to the position shown in'Figurcs 2 and 9 to 12, the pipe 38 will be connected to the return pipe 4,3 due to the communication between the chamber A and recess by means of the registration of the oriiices 85 wlt'n said recess. AAt the lsame time,the oriflces 84 will be in registration with the recess 54 so as to establish communication between the conductor 28 and the Y 42 of the conduit 4| through the chamber B.- With the valve in this position, the operating uid delivered to the Y 42 by the pump 34 will be directed by the chamber B, conductor 2li,l tubing and annular space 20 into the lower end of the cylinder i9 through the port 2| so as to exert its force against the lower end .of thepiston 22 and lift the same with its plunger 23. Since the pipe 3 0 is connected to the return pipey 43, the spent fluid within the cylinder above the piston and within the tubing string 25 will be displaced through the chamber A and said pipes 38 and 43 into the storage tank 48.

Upon complete revolution of the valve element 28, the operation will be repeated with th'e iluid from the pump 34 again being directed through the Y 42, chamber A, pipe 30 and macaroni string 25 into the cylinder |-8 so as to again force the .piston and its plunger downwardly. It is mani-` l the Well uids within the displacement chamber I8 will be forced through the check valve l1 into -the annular space between the tubing and casing.

Of course, the standing valve I4 will be open to admit the well fluids tothe chamber and the check valve I1 will be closed to prevent the ilow of said fluids from the casing upon the upstroke of the piston and its plunger.

by the upper surface of the piston is of 'a greater cross-sectional area than the underside thereof, with the result that a. greater volume of operating fiuid is requiredto lower said piston than to lift the same an equal distance. Since there is a positive dlierential in the volume of operating uid requiredfor the upstroke and downetrekeefmepietonzzutieneeeeeerytnettne control valve be so constructed that the proper volume will be delivered to each surface of said piston. Although the differential in cross-sectional areas is determined by the cross-sectional area of the plunger 23; forthe purposes of illustration. it will be assumed that the upstroke of said piston will require two gallons of huid and that three gallons will be required for an equal downstroke thereof, or a total of five gallons per complete reciprocation. Since the valve element makes one complete revolution foi-.each reciprocation of the piston, said element must proportion the live gallons of operating fluid delivered to the conductor 29 and pipe 20 during each revolution, three gallons being delivered to the latter and two gallons to the former. f course, the

speed of the positive displacement pump 3l must be regulated so as to deliver ilve gallons of operating fluid at a constant rate tothe valve 2l for each revolution of its element 21 and foreach reciprocation of the piston 22.

Due to the fact that the admission of the operating fluid to the' chambers A and B is controlled by the co-action of the recess and orifices I5 and the co-action of the recess Il' and .orifices 84, respectively, said recess-85 and orifices Il must be in registration for a sumcient duration of time to accommodate three gallons of the uid, whereas two gallons of said fluid must be accom# modated during the registration of said recess Il and oriilces Il. Therefore, the recess is of a greater circumferential length than the vrecess 64. the ratio being three to two in accordance with the volumes required by the diil'erential piston. Thus, the orifices l5 will be in registration with the recess 85 during approximately three-fifths or 216 degrees of each revolution of the 4valve element as shown by the angle X-X in Figure 8, while the orices 84 will register with the recess 84 for approximately two-fifths or 144 aeoaeoo A Y 8 revolution of the valve element as shown in Figures 9 to 12.

As has been explained', the valve element is rotated by the pump 34 through the sprockets 2| and 32, 'chain 3l and shaft 32, with the rate.

of speed of said element being controlled by the rate of speed of the pump through the ratio of said sprockets. This ratio, of course. is determined by the volume o! nuid delivered per minute by the positive displacement pump and the volume of fluid required to reciprocate the piston 22. If nve gallons of iluid are required for one reciprocation of the piston, as assumed, and it is desired to reciprocate said piston twelve times per minute. the speed of the pump must be regulated to deliver sixty gallons per minute. In the event. it is desired to .increase or decrease the number of reciprocations per minute of the piston, it will only be necessary to increase 'or decrease th'e speed of the pump, because the revolutions per minute of the valve element and the number oi reciprocations per minute of said piston is always the quotient of the capacity per minute of the pump divided by the volume of out of the method. the actuating fluid is delivered y by the pump 24 from the tank It through the conduit Il and Y 42 |to the ports 4l and It and reeeeeee s4 and es of 'the valve housing 21. with degrees of each revolutionfas shown by the an i gle Z-Z in Figure 9. During the angle of rotation X-X, the orifices are out oi' registration' with the recess Il, as shown in Figure 5, and the orifices are out of registration with the recess IB throughout the angle of rotation Z-Z, l

as shown in Figure 12. Since the recess and the orices 86 control the discharge of fluid from the chamberA into the return pipe 43 and are in communication simultaneously with registration of the orifices 84 and recess 64, said recess il is of the same circumferential length as the said recess M. so as to ypermit a ilow of fluid from said chamber A throughout the angle of'rotation Z-Z (Figure 11). As shown in Figure 7, the

-orices I6 are out of registration with the recess Il throughout the angle of rotation X-X. .The-

recess 81 is of substantially thel same length as the recess Il and is in registration with the orifices 81 throughout the angle of rotation X-X (Figure 8) to discharge fluid .from the chamber the valve element in the position shown in Figuree i; a end s te s. tile ermees se wm be in registration with the recess l5 so that the iluid will ilow through the chamber A, forward opening GI. forward groove 52, forward port 5I, pipe Il, and macaroni string 2i 'into the upper end of the cylinder Il, whereby the force of said fluid will be exerted against the upper surface of the piston 22 so as' to i'orce the same, together with its plunger-23, downwardly. The downwardly mov- B to the branch u of the pipe 42. Obviously,

communication between the recess l1 andoriilces l1 is shut on during'the angle of rotation Z-Z (Figure 10)` 4 As shown in Figures 5 to 8, the orifices Il and I1 Will be in registration with theirl'ospective recesses and theoriiices Il and el will be out of registration with their respective recesses during theangle of rotation Xf-X: or substantially throefifths ci each revolution of the valve element.

However, the ermee. siA and'n wm um Y tion and the-orinces II and l1 out of 0n, two-fifths, angle of rotation Z-Z. of tach ing plunger will displace the well iluids within the chamber Il into the annular space of the casing Il, as has been hereinbefore explained. Simultaneously with' the downward movement of the piston; the spent iluid within the cylinder il below said piston will be displaced outwardly through the ports 2l into the'annular space 2l and then upwardly throughthe tubing H and conductor 28. through the rear port Il, rear groove 52, rear opening I3, chamber B, and ori ilces l1, which are in registration with the recess 61. into the port 41, branch 4I of the return pipe Il and i'inally into the storage tank 40, Continued rotation of the valve element to the position shown lin Figures 2 and 9 to 12. will move the orii'lees Il into registration with the lrecess 84 and the orifices I8 into communication with the recess I8. The fluid delivered by the pump will then iiow through the chamber TB. rear opening Il, rear groove I2, rear port Il, pipe 20 and tubing Il into the annular space 2l and then A operation.

In commencing the operation of thehereinbefore described mechanism, it may happen that the piston will be at the end of its downstroke oiupstroke and the valve element will be in a position to admit a full volume of fluid to the upper or lower end of the cylinder, with the result that there would be no place forsaid fluid. In order to prevent damage to the mechanism in this event, a by-Dass line 08 extends from the conduit 4| to the pipe 43 and hasta pressure relief valve 69 connected therein, whereby the excess fluid 'may escape or bleed through the line' 68 and its valve 69 to the pipe 43 and be returned to the storage tank 40. Thus, the valve 69 serves to permit the escape of any' excess liquid during vthe operation of the pumping mechanism, After the beginning stroke, it is manifest that the rotation of the valve element will become automatically synchronized with the reciprocation of the piston so as to actuate the same in` the usual manner.

From the foregoing, it is obvious that thereciprocation of the piston 22 is positively and directly controlled by the surface valve 26 -with its valve element making one revolution for eachl reciprocation or complete stroke of said piston. Due to the use of this valve, it is possible to actuate a differential piston in a continuous, uniform 'manner with av fixed volume `of uid, such as is supplied by the positive displacement pump34. Although the mechanism has been described in connection with the operation of a displacement plunger type pump, it is to be understood that the invention is not tobe limited to the operation of a pump because the mechanism may be employed to control the actuation of any reciprocating member. Attention is again directed to the fact that the speed of the valve element is directly related to the speed of the surface pump, the speed of said element being determined by the capacity per minute of thel pump and the volume of iiuid displaced by the piston 22. which is the volume required to complete one reciprocation thereof, and is always the quotient of said pump capacity divided by the volume displaced during one reciprocation of said piston. This valve also permits the use of relatively inexpensive positive displacement pumps which are generally high-speed pumps. Due to the provision of the macaroni string 25, a closed Voperating system is had so as to eliminate the objection of admixing the actuating iiuid withl the well fluid, thereby permitting the use of The disposition of the openings ,of the rotary i" valve element and the snug engagementgbe whenl 1 said element and the bore 49 of the valve non ng assures a positive seal between said openings-,so

- as to prevent the leakage of fluid from one open- Lv It is also pointed, out that the valve element is supported bythe bearings 53 and not -by the valve housing bore, vwhereby i'ricm tional wear of said elementand'housing bore isl ing to another.

,reduced to a minimum.v v y It is pointed out that the reciprocation of the piston 22 maybe controlledby a multiplicity of mechanisms and that it is not essential to the method .to employ the valve 20 with its rotary valve element 28 for such purpose. Another form of control mechanism for carrying out the method is shown in Figures 1.3 to 17 and includes a' horizontally-disposed shaft |0 which has a sprocket 7|, similar to the sprocket 3| ofthe valve element 28, splined on one end thereof, whereby it may be positively rotated in a clockwise direction by the pump 34 through the shaft 32, sprocket 33, and continuousy chain '35 in exactly the same manner as said valve element. A plurality of' circular cams i4, 75, 16 and 'il are mounted on the shaft l0 in spaced relationship so as to be rotated therewith for actuating valves 94, 95, k9B and 97, which are preferably of the poppet type. The cams are of the usual construction and each cam has an arcuate or semicircular lobe made integral with the 'periphery thereof, as illustrated at |04, |05, |00 and |01 in Figures 14 to 17. The cam 'E4 and its lobe |04 are identical to the cam 10 and its lobe |06, while the cam '|'l with its lobe |07 is identical to the cam With its lobe |05. The lobes |04 and |06 are in horizontal alinement and are disposed 'in a plane diametrically-opposed to the plane of the lobes |05 and |01 which arelhorizontally alined. The circumferential length of the lobes |05 and |07 is greater than the circumierentiai length of the lobes |04 and $08,.

whereby said lobes |05 and |01 are comparable to the recesses 55 and 01 oi the rst form and said lobes |04 and |06 arethe equivalent of the recesses 04 and 66.

The valves 94, 95, 96 and 91 are of identical construction and each includes the kusual housing or casingj'l which has its interior divided into jan inlet chamber 19, and an outlet chamber 80 by a transverse,'horizontal partition 0|. Communication .between the inlet chamber 79 and outlet chamberl 80 is established by a central circular opening 82 which has its lower portion beveled to provide a valve seat 83. A valve head or disk 88, having its periphery beveled so as to engage the seat 83, is movable vertically 4within the chamber 19 andhas aA stem or rod 89 secured to the upper surface thereof. The valve stem 89 extends upwardly through the chamber 80 and is slidable through the bore of an annular 'collar or boss 90 which depends into said cham-v -ber from the'toppf the casing 18 for guiding the movement of said stem and the valve head 88. For holding the head 88 in engagement with the seat 03, a coiled or helical spring 9| `is confined upon the outer extremity ofthe stem y89l between the top of the valve casing and a disk or plate 92 carried by said stem.

The inlet chamber 19 of the valve 94 communicates-with the Y 42 of the conduit 4|,while the conductor 29 is'connected in the outlet chamw ber 80 of said valve to establish communication f between said chamber and the tubing (Figure 14) whereby the valve serves to control the fl'ow ll Y Y of operating iiuid from the pump 84 to the lower end of the cylinder I! in substantially the same manner as the orifices I4 of the rotatable valve element 29. As shown in Figure 17, the inlet and outlet chambers of the valve ll establish communication. between one end of the branch 42 of the conduit 4| and the pipe 30 which is connected to the macaroni string 2l, with the result that the flow of operating fluid from the pump 34 to the` upper end of the cylinder I! is controlled by said valve. A branch 1I is connected to the pipe 30 for conducting the spent iluid from the upper end of the cylinder upon the betweenthe branch 1I of the pipe Il and the return pipe 43 as shown by the dotted arrows in Figure 13, whereby the operating fluid delivered by the pump will be conveyed to the lower end of the cylinder I9 so as to raise the piston and the spent duid above said piston may be discharged through the valve I4 into said return pipe.

.It is readily apparent that the valves l and 91 commence opening when the point D of the cams 1l and 11 engage the rollers of the respective rocker arms of said valves and the valves upstroke of the piston 22 and has its free end communicating with the return pipe 43 through the inlet and outlet chambers of the valve S (Figure 16). During the downstroke of the piston. the spent :duid within the cylinder below the piston is conveyed from the conductor 2l through a connected branch 12 through the chambers of the valve 91 to the branch of the return pipe 43 as shown in Figure l5. Thus, the valves 95, 96 and 91 serve the same purposeand accomplish the identical results as the orifices 85, 88 and 81, respectively, of the valve ele.

For controlling the movement of the valve head 88, a rocker arm or lever Il is plvotally mounted above each valve on an upstanding bracket or standard 89 which is preferably made integral 94 and I8 arefully closed at this point. The valves I4 and I6 remain closed until the point C of each cam engages and passes beyond each roller. At this point, the lobes |04 and IIII of the cams 14 and 18 will engage the rocker arm rollers of the valves $4 and II so as to commence opening said valves. 'I'hese valves will remain open and the valves 9i and 91 will remain closed until the point D again passes beneath the roller. Thus, during the angle of rotation, C-D, the valves 94 and 90 will be open and the valves l! and Sl'will be closed. -However, the valves 94 and I6 will be closed and the valves 45 and Il' open during theangle of rotation, D-C.

with the upper portion of the valve casing 1l.

One end of the rocker arm engages the upper end of the valve stem 89. while the other end of said arm carries a roller or wheellll for engaging the periphery oi the respective cam of the valve.

Due to the provision of the spring 8l, each valve stem 8% is constantly urged upwardly into engagement with its rocker arm so that the roller of said arm will be in constant engagement with and ride upon the peripheral surface of its cam.

-Since the cams are constantly rotated bythe shaft 10, the lobes of said cams will swing the rocker arms about their pivots to depress the valve stems 80 and move the valve heads Il downwardly away from their seats thereby permitting a flow of duid through the valves as shown in Figures and 17. When the lobes move from beneath the rollers of the rocker arms (Figs. 14 and 16), the springs 9| will exert their force to raise vthe valve stems and again move the valve heads into engagement with their seats. Thus, the springs serve to maintain the valves in their closed position, while the lobes of the cams open said'valves. Also, the pressure of the fluid within the chambers 10 exerted against the lower surfaces of the valve heads will tend to assist the springs in holding the valves closed.

With the shaft 1l and cams in the position shown in Figures 14 to 17, the valves I4 and n will bel closed andthe valves il and $1 open,`

Due to the fact that it has been assumed that three gallons of operating fluid are required to Alower the piston 22, and two gallons for lifting the same, the peripheral surfaces of the lobes Ill and Ill of the cams 1l and 11, which actuate the valves 08 and" to control the flow of uid during the downstroke of the piston, engage their respective rocker arm 4rollers during approximately three-fifths or 218 degrees of each revolution of the shaft 1l. The peripheral surfaces of the lobes '|.l4 and |46 of the cams 14 and 1I engage their respective rocker arm rollers during approximately two-mths or 144 degrees of each revolution of said shaft to hold the valves 84 and Il open soas to control the ilow of fluid during the upstrolre of said piston. Therefore,

` it is obvious that the angle of rotation Cf-D and D-C are'comparable to the angles of clockwise rotation X-X and Z-Z, respectively. of the rotary valve element 28. In order to prevent the flow of iiuid to the valve 84 during the downstroke of the piston and to the valve Sl upon the upstroke of said piston, suitable check valves IUI are mounted in the conductor 2l and pipe 3l adjacent said valves. Similar check valves |02 are connected in the return pipe 4I and its branch 4I adjacent the valves and l1 for pre.-

thereby permitting a sow or operating suis from the pump 24 to the pipe 30, macaroni string 25,

and the upper end of the cylinder Il soas to. force the piston 22 downwardly. At the saine time. the fluid within the cylinder below the piston and within the space 2l, tubing and conductor-20 will be permitted to escape through the branch 12 and valve l1 into the branch 4l of the return .pipe .43. Upon rotation of the camsin a clockwise direction to the positionv shown in dotted lines, the valves Il and I1 be closed and the valves 94 and `open as shown by the dotted lines in Figures 14-1'1. The opening o1 these" valves will establish communication between the Y 42 of the conduit 4| and the vconductor 2l and venting the iiow of fluid from said pipe and its branch to said valve. It is readily apparent that this modified form of actuating mechanism will control the operation of a differential piston in exactlythe same manner as the nrst form of the invention which includes the rotary valve ele- The foregoing description of the invention is explanatory thereof and various changes in the sise,- shape and materials. as well as in the def tails of' the illustrated construction, may be made. within the scope of the appended claims, without departing from the spirit of the invention.

What I claim and desire to secure by Letters Patent is: Y

1. In a reciprocating apparatus, a mechanism including. a cylind a fluid-responsive member movable in the cylinder, means for conducting a hydraulic fluid to said cylinder for reciprocating the member-,the surfaces of said member exposed 13 the strokes of the member. means for controlling the ow of the fluid to the cylinder so as to proportion the same in accordance with the areas of said member. and means for actuating 4and supplying hydraulic, uid to the control means.

2. A mechanism as set forth in claim 1 wherein the control means includes constantly rotating means driven by the actuating and supplying means and synchronized with the reciprocation of the duid-responsive member.

3. A mechanism as set forth in claim 1 wherein the control means includes a'constantly rotating valve element driven by the actuating and supplying means andsynchronized with the reciprocation of the iuid-responsive member.

4. A mechanism asset forth in claim 1 wherein the control means includes valves and constantly rotating cam means synchronized with the reciprocatio'n of the duid-responsive member and driven by the actuating and supplying means'for actuating the valves.

5. An actuating mechanism for a reciprocating element including, a cylinder, a piston arranged to reciprocate within the cylinder, means for conducting a hydraulic uid to and from said cylinder for reciprocating the piston, one surface of said piston being of a greater cross-sectional area than the other surface thereof `so that one stroke of the piston requires a greater volume of fluid than the other stroke thereof, a pump for supplying -a xed volume of uldv-to the conducting means. and valve means interposed between the pump and conducting means for controlling the volume offluid supplied to said conducting means, the valve means including constantly rotating means driven by said pump for proportioning the volume of duid supplied to the conducting means in accordance with the areas of the piston sulsrces for controlling the reciprocation of said p n.

6. An actuating mechanism as set forth in `claim 5 wherein the constantly rotating means consists of a rotary valve element for simultaneously controlling the flowA of the :duid to and from .the cylinder.

7. An actuating mechanism as set for the in fluid to and from the cylinder, the constantly rotating means consisting lof cam means for actuating the valves.

8. An actuating mechanism for a reciprocating element including, a cylinder. a piston arranged to reciprocate within the cylindenmeans for conducting a hydraulic iiuid to the lower end of said cylinder to raise the piston, additional means for conductingthe fluid to the upper end of the cylindex' to lower said piston, one surface of the piston being of a greater cross-sectional area than the other surface thereof so that one stroke of said piston requires a greater volume of fluid than the other stroke thereof, valve means communicating with the conducting means for controlling the flow of the uid'thereto, the valve means including constantly rotating means synchronized with the reciprocation of the piston for v proportioning the volume. of fluid admitted to each conducting means in accordance with the areas of the piston surfaces so as to positively control'the reciprocation of said piston, and a pump for supplying a ixedvolume of fluid to saidvalve means and for driving the constantly rotatlng means. y l

9. An'actuating mechanism as set forth in claim 8 wherein the constantly rotating means consists of a rotary valve element.

10. 'An actuating mechanism as set forth in claim 8 wherein the valve means includes valves, the constantly rotating means consisting bi' cam means for actuating the valves.

11. A system of the character described including, a reciprocating member having opposite actuating surfaces of unequal areas.- a huid cir` culating conduit having connection with the member, a source of iiuid supply connected in the conduit, a pump connected in said conduit bev tween the supply source and'said member, and

claim 5 wherein the valve means includes valves for simultaneouslycontrolling the flow of the means actuated by the pump for controlling the f flow otvfiuid to and from the opposite surfaces of the member in proportion to the areas thereof, f

the control vmeans including constantly rotating means driven by saidvpump and synchronized with the reciprocation of said member for proportioning the now of fluid in accordance with the areas ot said opposite member surfaces.

' JOHN M. SHDER. 

